Mesogenic 4-acryloyloxy- and 4-(2,3-epoxypropoxy)phenyl 4-alkoxybenzoates

Article abstract of DOI:10.1134/S1070428013020061

Procedures were developed which made it possible to synthesize in good yields homologs of 4-acryloyloxyphenyl 4-alkoxybenzoates (C₃, C ₅, C₇, C₈) and of 4-(2,3-epoxypropoxy)phenyl 4-alkoxybenzoates (C₅, C₇). The substituted phenylbenzoates obtained exhibit the enantiotropic nematic mesomorphism in a sufficiently wide temperature range. The studied compounds have absorption maxima in the near UV region and a high temperature of decomposition beginning.

Full text of DOI:10.1134/S1070428013020061

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2013, Vol. 49, No. 2, pp. 208−211. © Pleiades Publishing, Ltd., 2013.
Original English Text © E.S. Syrbu, O.V. Potemkina, I.V. Novikov, S.A. Kuvshinova, O.I. Koifman, V.V. Aleksandriiskii, V.A. Burmistrov, 2013, published in
Zhurnal Organicheskoi Khimii, 2013, Vol. 49, No. 2, pp. 219−222.
Mesogenic 4-Acryloyloxy-
and 4-(2,3-Epoxypropoxy)phenyl 4-Alkoxybenzoates
E. S. Syrbua, O. V. Potemkinab, I. V. Novikova, S. A. Kuvshinovaa,
O. I. Koifmana, V. V. Aleksandriiskiic, and V. A. Burmistrovc
aResearch Institute of Macroheterocyclic Compounds at Ivanovo State University of Chemical Engineering,
Ivanovo,153000 Russia
e-mail: sofya.kuv@yandex.ru
b Ivanovo Institute of State Fire Fighting Service of the Russian Emergencies Ministry, Ivanovo, Russia
c Institute of Solution Chemistry, Russian Academy of Sciences, Ivanovo, Russia
Received April 17, 2012
Abstract—Procedures were developed which made it possible to synthesize in good yields homologs of
4-acryloyloxyphenyl 4-alkoxybenzoates (C3, C5, C7, C8) and of 4-(2,3-epoxypropoxy)phenyl 4-alkoxybenzoates
(C5, C7). The substituted phenylbenzoates obtained exhibit the enantiotropic nematic mesomorphism in a sufficiently
wide temperature range. The studied compounds have absorption maxima in the near UV region and a high
temperature of decomposition beginning.
DOI: 10.1134/S1070428013020061
Low-molecular substituted phenyl benzoates owing
to their specific properties are promising compounds
for practical application. For instance, the liquid crystal
compositions based on phenyl benzoates are interesting
for application in the information mapping facilities
due to the bwide range of the mesophase existence, low
viscosity, and high dielectric anisotropy [1]. The inter-
est to substituted phenyl benzoates originates also from
the possibility of their application as liquid crystalline
stationary phases in GLC for solving versatile analytic
problems, first of all, for the separation of spatial isomers
of organic substances [2]. Besides the phenyl benzoates
with the chemically active substituents are nontoxic and
non-coloring light-resistant stabilizers for polyolefins
and poly(vinyl chloride) [3]. The introduction into the
rigid core of phenyl benzoate of epoxy and acryloyloxy
groups followed by polymerization provide a possibility
to synthesize liquid crystalline polymers of comb-shaped
polymers for the new field of optoelectronics creating
flexible electrooptic gadgets, including displays [4].
properties, and the estimation of the opportunities to
use the obtained substances as the stabilizers of polymer
materials.
4-Acryloyloxy- (IIa–IId) and 4-(2,3-epoxypropoxy)
phenyl (IIIa, IIIb) 4-alkoxybenzoates were synthesized
along the following scheme.
4-Hydroxyphenyl 4-alkoxybenzoates Ia–Id were
obtained by the reaction of freshly prepared 4-alkoxy-
phenylcarbonyl chlorides with a five-fold excess of hy-
droquinone in anhydrous pyridine at 30°C within 10 h [5].
Acryloyloxy-substituted phenyl benzoates IIa–IId were
synthesized from esters Ia–Id by the reaction with acry-
loyl chloride in the presence of triethylamine as acceptor
of the liberating HCl in chloroform at 60°C within 3.5 h.
By varying the reagents ratio, amount of the phase transfer
catalyst Et4NBr, concentration of the water solution of
NaOH, reaction time and epoxidation temperature we
determined the optimum conditions of the preparation
of epoxy-substituted phenyl benzoates IIIa, IIIb: The
ratio of compound I–epichlorohydrin–anhydrous sodium
hydroxide was 1:30:2, the reaction was carried out at
70°C over 5 h, without catalyst . The obtained substituted
phenyl benzoates IIa–IId, IIIa, IIIb were recrystallized
and dried in a vacuum to the constant temperatures of the
In this connection the goal of this research was the
development of optimum procedures for the synthesis of
4-acryloyloxy- and 4-(2,3-epoxypropoxy)phenyl 4-alk-
oxybenzoates, the investigation of their mesomorphic
208

MESOGENIC 4-ACRYLOYLOXY- AND 4-(2,3-EPOXYPROPOXY)PHENYL 4-ALKOXYBENZOATES
Scheme.
209
OH
OH
COOH
COCl
O
SOCl2
HO
Py
CnH2n+1
O
CnH2n+1
O
CnH2n+1
O
Iа_Id
O
O
O
Cl
CnH2n+1
O
Et3N
O
IIа_IId
Iа_Id
O
O
Cl
CnH2n+1
O
O
NaOH
O
IIIа, IIIb
I, II, n = 3 (a), 5 (b), 7 (c), 8 (d); III, n = 5 (a), 7 (b).
phase transitions and to the absence of impurity signals
in the 1H NMR spectra.
dangerous for the majority of polymers.
The temperatures (°C) of the phase transitions
from crystal to nematic phase (C→N) and from
nematic phase to isotropic liquid (N→I) of compounds
obtained measured by the method of polarization
thermomicroscopy are listed in the table.
The composition and the structure of compounds
obtained were established from elemental analysis and
1H NMR spectra. The theoretical calculations of δ values
were performed by the method B3LYP/6-311G(O, P) [6],
the shielding constants were calculated by GIAO method
[7]. The shielding constants were used in calculations of
chemical shifts with respect to TMS. It should be noted
that for all molecules the theoretical δ values are some-
what larger than the experimental ones. This discrepancy
arises from the calculations for isolated molecules in the
gas phase without accounting for the effect on the chemi-
cal shifts produced by the solvation surrounding. At the
same time a stable correlation was observed between the
calculated and experimental δ values.
Compound no.
C
N
IIa
IIb
IIc
91.3
81.8
68.1
116.3
106.8
97.6
IId
IIIa
64.8
41.5
95.8
67.3
IIIb
42.1
57.8
Consequently phenyl benzoates IIa–IId, IIIa, IIIb are
enantiotropic liquid crystals, they possess an insignificant
thermal stability of the mesophase and a sufficiently large
range of its existence.All compounds under investigation
above the melting point are melts of low viscosity exhibit-
ing schlieren textures in the polarized light characteristic
of the nematic mesaphase. The comparison of the phase
transitions of compounds II and III indicates the stabili-
zation both of nematic and crystal phases at introducing
Electron absorption spectra are interesting for the
qualitative estimation of the possibility to use the com-
pounds synthesized as modifiers of polymer materials. It
has been shown by an example of compounds IIa, IIIa
that the studied compounds have an inherent absorption
in the near UV spectral region (see EXPERIMENTAL),
consequently, at their presence in the composition based
on macromolecular compounds they shoul screen the
polymer matrix in this spectral range which is the most
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 49 No. 2 2013

SYRBU et al.
210
into the structure of the acryloyloxy substituent. Within
each series the temperatures of the nematic-isotropic
transition regularly decrease with the elongation of the
terminal alkyloxy substituents due to the loosening effect
of the aliphatic substituents.
with water, the organic layer was separated, dried with
Na2SO4, the solvent was distilled off, the residue was
twice recrystallized from ethanol. Yield 2.48 g (76%),
white crystals, mp 91.3°C. UV spectrum, λmax, nm (lgε):
263 (4.01). 1H NMR spectrum, δ, ppm: 0.95 t (3H,
CH3, J 7.41 Hz), 1.50 d (2H, CH2, J 7.04 Hz), 3.95 d
(2H, CH2O, J 6.46 Hz), 5.55 d (2H, =CH2, J 10.40 Hz),
5.98 m (1H, CH=), 6.88 d (2Harom, J 17.97 Hz), 7.09 m
(4Harom), 7.95 d (2Harom, J 8.83 Hz). Found, %: C 69.57;
H 5.36; O 24.40. C19H18O5. Calculated, %: C 69.94;
H 5.52; O 24.54.
Some chemical processes occurring in the substance
at heating are known to be accompanied with the change
of mass (thermal oxidation, destruction, etc.) [8]. The
thermal stability of mesogenes IIa, IIIa were estimated
by the thermogravimetric analysis. We chose as criteria
the temperatures of the decomposition beginning (tdb,
°C) where the thermogravimetric curves deviate from
the initial zero value, and the temperature of the loss of
70% of the sample mass (t70%, °C):
Esters IIb–IId were obtained similarly.
4-Acryloyloxyphenyl 4-allyloxybenzoate (IIb).
1
Yield 2.76 g (78%), white crystals, mp 81.8°C. H NMR
spectrum, δ, ppm: 0.98 t (3H, CH3, J 7.38 Hz), 1.30 m
[6H, (CH2)3], 3.96 d (2H, CH2O, J 6.43 Hz), 5.58 d (2H,
Compound no.
tdb
t70%
446
453
=CH2, J 10.38 Hz), 6.01 m (1H, CH=), 6.93 d (2Harom
,
IIa
337
362
J 17.95 Hz), 7.11 m (4Harom), 8.09 d (2Harom, J 8.83 Hz).
Found, %: C 70.05; H 6.09; O 21.97. C21H22O5. Calcu-
lated, %: C 71.17; H 6.26; O 22.57.
IIIa
Thus the obtained substituted phenyl benzoates pos-
sess a thermal stability exceeding the temperature of
the processing of the majority of macromolecular com-
pounds, and consequently, they can be used as modifiers
of the polymer materials, in particular, in the compositions
underlain by polyolefins and poly(vinyl chloride).
4-Acryloyloxyphenyl 4-heptyloxybenzoate (IIc).
1
Yield 2.86 g (75%), white crystals, mp 68.1°C. H NMR
spectrum, δ, ppm: 0.96 t (3H, CH3, J 7.38 Hz), 1.40 m
[10H, (CH2)5], 3.97 d (2H, CH2O, J 6.44 Hz), 5.51 d (2H,
=CH2, J 10.37 Hz), 6.01 m (1H, CH=), 6.90 d (2Harom
,
J 17.96 Hz), 7.06 m (4Harom), 8.03 d (2Harom, 8.83 Hz).
Found, %: C 72.13; H 6.24; O 20.76. C23H26O5. Calcu-
lated, %: C 72.23; H 6.85; O 20.92.
EXPERIMENTAL
Electron absorption spectra were recorded on a spec-
trophotometer Perkin Elmer Lambda 20 in CHCl3. H
4-Acryloyloxyphenyl 4-octyloxybenzoate (IId).
Yield 3.05 g (77%), white crystals. mp 64.8°C. H NMR
1
1
NMR spectra were registered in CDCl3 on a spectrometer
Bruker Avance III at operating frequency 500 MHz; in-
ternal reference TMS. The phase transition temperatures
of the compounds obtained were measured and the study
of textures was performed on a polarization microscope
Polam P211 equipped with a heating block. The accuracy
of the measurements of the phase transition temperatures
was ±0.2°C. The thermogravimetric analysis was carried
out on a NETZSCH instrument in the dynamic mode in
an argon flow, heating rate 5 deg min–1, weight of the
sample 2–5 mg.
spectrum, δ, ppm: 0.93 t (3H, CH3, J 7.37 Hz), 1.40 m
[12H, (CH2)6], 3.91 d (2H, CH2O, J 6.45 Hz), 5.50 d. (2H,
=CH2, J 10.38 Hz), 6.08 m (1H, CH=), 6.90 d (2Harom
,
J 17.97 Hz), 7.01 m (4Harom), 7.99 d (2Harom, J 8.83 Hz).
Found, %: C 72.61; H 6.89; O 19.78. C24H28O5. Calcu-
lated, %: C 71.73; H 7.07; O 20.20.
4-(2,3-Epoxypropoxy)phenyl 4-allyloxybenzoate
(IIIa). A mixture of 3 g (0.01 mol) of 4-hydroxyphenyl
4-allyloxybenzoate, 0.8 g (0.02 mol) of sodium hydrox-
ide, and 27.8 g (0.3 mol) of epichlorohydrin was stirred
for 5 h at 60–62°C, the reaction mixture was cooled,
filtered, the filtrate was evaporated to dryness. The solid
residue was twice recrystallized from ethanol. Yield 2.42
4-Acryloyloxyphenyl 4-propyloxybenzoate (IIa). To
a solution of 2.72 g (0.01 mol) of 4-hydroxyphenyl 4-pro-
pyloxybenzoate in 50 ml of chloroform was added 1.01 g
(0.01 mol) of triethylamine. The solution was stirred for
30 min, afterwards within 1 h was added dropwise 0.9
g (0.01 mol) of acryloyl chloride. The reaction mixture
was stirred for 3 h at 40–45°C, cooled, washed thrice
g (68%), white crystals, mp 41.5°C. UV spectrum, λmax
,
1
nm (lgε): 272 (4.07). H NMR spectrum, δ, ppm: 0.95 t
(3H, CH3, J 6.62 Hz), 1.40 m [6H, (CH2)3], 2.65 m (2H,
Ht), 3.17 m (1H, Ht), 4.05 d (4H, CH2OAr, OCH2Ht,
J 6.46 Hz), 6.93 d (2Harom, J 8.83 Hz), 7.10 d (2Harom
,
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 49 No. 2 2013

MESOGENIC 4-ACRYLOYLOXY- AND 4-(2,3-EPOXYPROPOXY)PHENYL 4-ALKOXYBENZOATES
211
2. Lobanova, S.A., Shcherbakova, O.A., Burmistrov, V.A.,
and Koifman, O.I., Izv. Vuzov, Ser. Khim. Khim. Tekhnol.,
1989, vol. 63, p. 1223; Fokin, D.S., Cand. Sci. (Chem.)
Dissertation, Ivanovo, 2010; Kuvshinova, S.A. RF Patent
2339616, 2007. RF Byull. Izobr., 2008, no. 33; Fokin, D.S.,
Kuvshinova, S.A., Burmistrov, V.A., Blokhina, S.V., and
Koifman, O.I., Zhidk. Krist., Ikh Prakt. Isp., 2009, vol. 27,
p. 71.
J 8.82 Hz), 7.21 d (2Harom, J 8.84 Hz), 8.13 d (2Ha-
rom, J 8.83 Hz). Found, %: C 70.43; H 6.36; O 22.34.
C21H24O5. Calculated, %: C 70.78; H 6.74; O 22.47.
4-(2,3-Epoxypropoxy)phenyl 4-heptyloxybenzo-
ate (IIIb) was obtained similarly. Yield 2.70 g (70%),
1
white crystals, mp 42.1°C. H NMR spectrum, δ, ppm:
0.98 t (3H, CH3, J 6.61 Hz), 1.40 m [10H, (CH2)5],
2.60 m (2H, Ht), 3.11 m (1H, Ht), 3.97 d (4H, CH2OAr,
OCH2Ht, J 6.45 Hz), 6.88 d (2Harom, J 8.82 Hz), 7.01 d
(2Harom, J 8.84 Hz), 7.16 d (2Harom, J 8.83 Hz), 8.09 d
(2Harom, J 8.83 Hz). Found, %: C 71.08; H 7.13; O 20.57.
C23H28O5. Calculated, %: C 71.88; H 7.29; O 20.83.
3. Kuvshinova, S.A., Fokin, D.S., Novikov, I.V., Litov,
K.M., and Burmistrov, V.A., Zhidk. Krist. Ikh Prakt.
Isp., 2008, vol. 25, p. 5; Fokin, D.S., Kuvshinova, S.A.,
Vasil’ev, D.M., and Burmistrov, V.A., Zhidk. Krist. Ikh
Prakt. Isp., 2009, vol. 29, p. 14; Fokin, D.S., Kuvshinova,
S.A., Burmistrov, V.A., and Koifman, O.I., Zhidk. Krist.
Ikh Prakt. Isp., 2009, vol. 28, p. 78.
ACKNOWLEDGMENTS
4. Zhidkokristallicheskie polimery (Liquid Crystal Polymers),
The study was carried out under the financial
support of the Presidium of the Russian Academy of
Sciences (Program of basic research no. 24) and of
the Russian Foundation for Basic Research (grant
no. 12-03-00370-a).
Plate, N.A., Moscow: Khimiya, 1988, p. 416.
5. Schroeder, D.C. and Schroeder, J.-P., J. Org. Chem., 1972,
vol. 37, p. 1425.
6. Becke, A.D., J. Chem. Phys., 1993, vol. 98, p. 5648.
7. Ditchfield, R., Mol. Phys., 1974, vol. 27, p. 789.
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